Effect of active noise-cancelling headphones combined with music therapy on postoperative recovery quality after general anaesthesia for ankle fracture ORIF: a study protocol for a single-centre, four-arm 2×2 factorial randomised controlled trial in China.

INTRODUCTION: Operating room noise levels during ankle fracture open reduction and internal fixation (ORIF) can reach levels well above the WHO recommended 35 dB(A) threshold for hospital treatment rooms. Neuroimaging evidence confirms that primary auditory cortex remains responsive to acoustic stimuli even under general anaesthesia (bispectral index 40-60), suggesting intraoperative noise may trigger stress responses via subcortical pathways. Active noise-cancelling (ANC) headphones combined with music therapy represent a promising non-pharmacological intervention for enhanced recovery after surgery protocols, yet no study has employed factorial design to isolate the independent and interactive effects of noise reduction and music therapy on postoperative recovery. METHODS AND ANALYSIS: This prospective, randomised, participant and outcome-assessor-blinded, four-arm, 2×2 factorial design trial will enrol 224 adult patients (aged 18-65 years) scheduled for elective ankle fracture ORIF under standardised anaesthesia combining saphenous nerve block with popliteal sciatic nerve block plus general anaesthesia at Deyang Sixth People's Hospital, Sichuan, China. Patients will be randomised 1:1:1:1 to: (1) NC-MT group: ANC plus personalised music; (2) NC group: ANC only; (3) MT group: passive isolation plus personalised music and (4) Sham group: passive isolation only. All groups will wear identical Soundcore Space One headphones, applied after anaesthesia induction (loss of consciousness) and removed before emergence (Bispectral Index<60), so that patients cannot perceive between-group difference in device operating mode. The primary outcome is the 15-item Quality of Recovery score (QoR-15) at 24 hours postoperatively. Secondary outcomes include pain (Visual Analogue Scale), anxiety (6-item State-Trait Anxiety Inventory), sleep quality (Richards-Campbell Sleep Questionnaire), melody recognition test, opioid consumption and adverse events. ETHICS AND DISSEMINATION: This study was approved by the Institutional Review Board of Deyang Sixth People's Hospital, Sichuan, China, on 23 December 2025 (DSLYIRB-2025-11) and is conducted in accordance with the Declaration of Helsinki and Good Clinical Practice of the International Council for Harmonisation (ICH-GCP) guidelines. Written informed consent will be obtained from all participants prior to enrolment. Findings will be disseminated through peer-reviewed publication and academic conference presentations. TRIAL REGISTRATION NUMBER: ChiCTR2600123100.